"OS.X Macarena poses no viable threat as currently conceived. Although we don't have our hands on the virus source code, according to Symantec (who initially publicized the virus last week) OSX.Macarena can infect neither PowerPC-exclusive binaries, nor Universal binaries. It can only affect binaries that are Intel-specific. That would include various system files, but since OSX.Macarena can only infect files in its own directory and has no means of gaining the privileges necessary to escalate into directories where most system files are stored, the the threat level is mitigated."